Since its onset, the AIDS epidemic has posed a series of complex ethical and policy challenges, inevitable, with a public health threat rooted in the most intimate behaviors. Over the past decade Dr. Bayer has studied and written about these issues. Over the five-year award period Dr. Bayer win, in the context of his positions as Professor at the Columbia University School of Public Health and as a member of the HIV Center for Clinical and Behavioral Studies at the New York State Psychiatric Institute, continue his studies of the ethical, legal, and policy issues posed by the AIDS epidemic. Some of his studies will entail careful empirical analysis; others will involve ethical and conceptual work on ethics, law, and policy. Three major research projects will be conducted: a study of the way in which individuals with HIV infection think about their decision to disclose or conceal their HIV status from sexual partners; an analysis of how the AIDS epidemic has affected the understanding of what it means to be a physician (relying primarily on oral histories); a comparative study of how economically advanced, democratic nations responded to blood transfusion-associated AIDS, the timing of the adoption of protective measures, and the extent to which those who were infected were provided with compensation. In addition, building on his past work on the ethics of HIV screening, and matters affecting the reproductive rights of women with HIV, Dr. Bayer will continue to investigate the ethical, legal, and policy debate surrounding the testing of pregnant women and newborns. He will also continue his ongoing studies of tuberculosis control efforts that entail the revision of public health regulations in the face of the rise of multi-drug resistant tuberculosis and contemporary constitutional norms limiting the exercise of state powers. Dr. Bayer will work closely with behavioral scientists at the HIV Center for Clinical and Behavior Studies to explore the ethical and policy implications of their work. This collaboration is crucial not only for Dr. Bayer's own research but for his colleagues as well. He will continue to mentor pre- and post-doctoral students who have a special interest in the ethical and policy dimensions of the AIDS epidemic.